1 Deserts are some of the driest places on Earth. They receive very little rainfall. They are so dry that most plants cannot survive in them. A desert is defined as a region that receives less than 250 millimeters, or about 10 inches, of precipitation in a year. Most people think of deserts as very hot, sandy places. This can be true, but there are many kinds of deserts. Deserts can be hot or cold. The Sahara Desert in Africa is a hot, sandy desert. Most of the continent of Antarctica is a desert, too. Antarctica is covered in ice and snow, but very little snowfall occurs each year. Temperatures remain quite low, even in the summer. Only a small amount of the continent's ice melts in a given year.2 Antarctica is an extreme desert. It is the coldest place on Earth. There is no other place like it. In contrast, the Lut Desert in Iran has been called the hottest place on Earth. It has been measured at nearly 160 degrees Fahrenheit! It is so hot that nothing can survive there, not even bacteria. Earth has another extreme desert. It is the driest place on Earth. It is the Atacama Desert.3 In the northern part of the narrow South American country of Chile lies the Atacama Desert. The desert lies between two mountain ranges. The Chilean Coast Range runs along the western side of the desert. The Andes Mountains run along the desert's eastern border. The mountains block clouds, and therefore, moisture from crossing over into the desert.